GPU: Build most of the gpu as a single DLL.

gpu/command_buffer/client/ring_buffer.h

Index: gpu/command_buffer/client/ring_buffer.h
===================================================================
--- gpu/command_buffer/client/ring_buffer.h	(revision 124716)
+++ gpu/command_buffer/client/ring_buffer.h	(working copy)
@@ -8,6 +8,8 @@
 #define GPU_COMMAND_BUFFER_CLIENT_RING_BUFFER_H_
 
 #include <deque>
+
+#include "../../gpu_export.h"
 #include "../common/logging.h"
 #include "../common/types.h"
 
@@ -17,7 +19,7 @@
 // RingBuffer manages a piece of memory as a ring buffer. Memory is allocated
 // with Alloc and then a is freed pending a token with FreePendingToken.  Old
 // allocations must not be kept past new allocations.
-class RingBuffer {
+class GPU_EXPORT RingBuffer {
  public:
   typedef unsigned int Offset;